Medically reviewed by Neka Miller, PhD on September 28, 2020. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
As the current pandemic caused by the novel coronavirus continues, researchers have developed different tools and methods to reduce the spread of the virus. Since the beginning of the pandemic, one of the most important tools has been testing. Tests play an integral role in determining who has COVID-19 or may have had the virus in the past, which can provide vital epidemiological information, help a patient understand potential next steps, and help medical experts better understand methods of transmission.
Many people have plenty of questions about the testing process. What type of coronavirus tests can you expect? How long do swab test results take? Read on to learn more about COVID-19 testing procedures—whether it’s antibody testing or a PCR coronavirus test kit.
There are three main types of coronavirus tests available: PCR tests, antigen tests, and antibody tests.
PCR tests determine if you have an active SARS-CoV-2 coronavirus infection. This is done by checking a sample of nasal secretion (which may be collected with a nasopharyngeal swab) for the genetic material of the virus. In the case of COVID-19, this kind of viral testing is specifically referred to as RT-PCR, which stands for “reverse transcription polymerase chain reaction.” The RT-PCR test is widely regarded as the “gold standard” for COVID-19 testing.
Antigen tests detect specific proteins—known as antigens—that are unique to the coronavirus. Nasopharyngeal secretions are commonly used as the sample type for antigen testing, and positive results indicate a current infection. Rapid antigen tests have been developed that can generate results in just 15 minutes. However, while it may take longer to get results from an RT-PCR test, an antigen test has a higher chance of missing an active infection.
The human immune system creates antibodies in response to bacteria, viruses, and other potential microbial threats. The immune system creates these antibodies within a few days or weeks after being infected by the microbe. Antibodies are unique to the kind of microbe the immune system is responding to; COVID-19 antibody testing takes advantage of this fact by checking a blood sample for antibodies that are specific to SARS-CoV-2.
Antibodies themselves can stay in the bloodstream several weeks or even longer following recovery, which means that antibody tests are not reliable for diagnosing an active coronavirus infection — but are instead useful as a way to test for past infection.
The exact testing procedures can vary based on the type of test administered. For antibody testing, a health care professional takes a blood sample either by drawing blood from a vein in your arm or by pricking your finger. The sample is then tested in a lab to determine the presence of antibodies specific to the novel coronavirus.
Many people are more familiar with tests involving swabs. Both RT-PCR and antigen tests involve the use of a swab to collect a sample. Some tests may require a nasopharyngeal swab, during which the test administrator will insert a six-inch-long swab into a nostril to reach the back of the nasal passage. The swab is rotated for about 15 seconds, and the process is repeated through the other nostril. The swab is then sent to a lab for testing.
Other testing sites may use a combination of nasal swabs, throat swabs, and mucus samples. With nasal swabs, the swab is inserted two to three centimeters into each nostril, while a throat swab collects samples at the back of your throat. If you are coughing up mucus, the test administrator may also ask you to cough into a container.
Nasopharyngeal swabs are often intimidating. The average person just doesn’t insert things that deep into their nose, and while the procedure is generally not painful, it can be highly uncomfortable for some. However, studies show that samples taken from deeper in the nasopharynx have a higher viral concentration, which naturally makes for a more accurate and reliable COVID test and diagnosis.
Still, nasal and throat swabs have their place. If it means greater comfort and ease of testing, more testing sites may use the nasal and throat swabs. Furthermore, if you have nasal polyps, chronic nose bleeds, or other nasal conditions, talk to your provider about using a nasal swab instead of a nasopharyngeal swab.
The time it takes to test your sample and receive results can vary based on the type of test that was administered. COVID-19 antibody test results may be ready within the same day at some testing sites. Other sites may have to send tests out to a third-party testing facility. On average, you can expect to receive antibody test results within one to two days.
Some PCR tests may take only a few hours to yield results if the samples are tested on-site, or it may take a few days if the samples are sent elsewhere for testing. On average, you can expect to receive results from an RT-PCR test within two to five days.
Antigen tests were designed for fast results and rapid detection of the novel coronavirus. You can usually get results from an antigen test within 15 minutes. This is thanks to the fact that the test does not require any specialized laboratory equipment, and it can easily be done in a doctor’s office or a clinical setting.
Keep in mind that an increase in testing across the nation can mean a greater load on labs, which can contribute to longer-than-usual wait times for a lab result.
A positive result with an RT-PCR or antigen test means that you currently have an active coronavirus infection and should take the necessary steps to take care of yourself, self-isolate, and contact anyone who you may have been in contact with recently. False positives (results showing that you have the virus when you actually don’t) are generally rare, but they are not unheard of. Any positive result should be taken seriously, and you should immediately inform your healthcare provider.
While negative results from one of these tests can be reassuring, note that false negatives can occur based on when you were potentially exposed to the virus and the time that you took the test. For example, if you were tested immediately after exposure, you may not have enough of the virus in your system to show up on the test, resulting in negative results.
Antibody test results do not indicate whether you currently have an ongoing infection. Also note that, even with a positive result on an antibody test, there is no concrete evidence that the antibodies detected by these tests can actually prevent future infections. So until we know more about the virus and develop a feasible vaccine, do not consider yourself immune to the virus based on the results of an antibody test. That means taking all the necessary precautions, like wearing a mask and practicing proper social distancing, to protect yourself and those around you.
While there is still no known cure or vaccine for COVID-19, testing is quickly becoming an important tool for understanding the virus and preventing its spread. Everlywell provides FDA-authorized at-home testing kits that give accurate results typically within 24-48 hours of the lab receiving your sample.
For more information on what you need to know about coronavirus, check out the blog articles below.
1. Lim J, Lee J. Current laboratory diagnosis of coronavirus disease 2019. Korean J Intern Med. 2020;35(4):741-748. doi:10.3904/kjim.2020.257
2. Interim Guidance for Rapid Antigen Testing for SARS-CoV-2. Centers for Disease Control and Prevention. URL. Accessed September 28, 2020.
3. COVID-19 diagnostic testing. Mayo Clinic. URL. Accessed September 28, 2020.
4. COVID-19 Testing: What You Need to Know. Centers for Disease Control and Prevention. URL. Accessed September 28, 2020.
5. Antibody (Serology) Testing for COVID-19: Information for Patients and Consumers. US Food & Drug Administration. URL. Accessed September 28, 2020.
7. Coronavirus Testing Basics. US Food & Drug Administration. URL. Accessed September 28, 2020.
8. Coronavirus - testing. Centers for Disease Control and Prevention. URL. Accessed September 28, 2020.
9. Coronavirus - Prevent Getting Sick. Centers for Disease Control and Prevention. URL. Accessed September 28, 2020.